1. Field of Invention
This invention pertains generally to data storage and retrieval systems and, more particularly, to apparatus and a method for handling CD-ROMs in such systems.
2. Related Art
CD-ROMs (compact disc read-only memories) and other optical storage media have found increasingly wide use in recent years where relatively large amounts of data are to be stored and retrieved. To protect such media, they are usually placed in protective cases or enclosures, which in the case of CD-ROMs are known as "caddies".
To increase the amount of data which is available, CD-ROMs and other optical storage discs are sometimes arranged in groups or "libraries" with mechanisms for transferring the discs between storage locations and one or more transcribing units where data is written to or read from the them. Such systems are sometimes referred to as "juke boxes" because of their similarity to machines of that name for playing phonograph records, and one example of such a system is found in U.S. Pat. No. 5,206,845.
In order to transfer a disc or cartridge between a storage location and a transcribing unit, a transport mechanism must engage the case in which the disc is enclosed and withdraw the cartridge as a unit from its current location. The cases in which optical storage discs are commonly enclosed have ears or tabs at the corners thereof which can be engaged relatively easily by the transport mechanism. The caddies most commonly employed with CD-ROMs, however, have no such means, and can only be gripped by squeezing the opposite faces thereof. This does not always provide a good grip on the caddy, and the forces exerted on the case can damage the caddy and/or the disc therein.